1. Field of the Invention
The present invention relates to an air-intake module for an internal combustion engine, in which an air cleaner, a throttle body, a surge tank, intake manifold pipes and other components are integrated into a single module that can be mounted on the engine as a single unit.
2. Description of Related Art
An air-intake device for an internal combustion engine includes an air cleaner, a throttle body, a surge tank, an intake manifold and other components. A throttle valve installed in the throttle body is operated by an acceleration pedal, so that an amount of intake air is controlled. The intake air is mixed with fuel and supplied to the engine. An air-intake module into which all components are integrated is disclosed, for example, in JP-A-6-81735 and EP-0523027-A2. It is possible to reduce the number of parts and to simplify an assembling process by integrating components in a single module.
In the conventional integrated modules, one end of a manifold is mounted on and fixed to the engine, and an air cleaner is disposed above the manifold. Therefore, a working space for mounting the module on the engine is covered by the air cleaner, and, accordingly, it is hard to mount the module on the engine. For example, in the air-intake module disclosed in JP-A-6-81735, an upper portion of a manifold is covered by an air cleaner case. The air cleaner case has to be disassembled from the module when the module is mounted on an engine. Otherwise, there is no working space for mounting. In the air-intake module disclosed in EP-0523027-A2, a whole rear portion of a mounting flange disposed at one end of a manifold is covered by an filter housing. Therefore, an air cleaner element disposed in the housing and its upper cover have to be removed from the module to mount the module on an engine.